Barack Obama never mentioned Mitt Romney when he spoke at the United Auto Workers Convention on Tuesday. But when Obama said “folks,” he meant Romney. When Obama said “these politicians,” he meant Romney. And when Obama said “some politicians,” he meant Romney.

It’s halftime in the 2012 election. The remaining Republican candidates are off squabbling with each other about who is more conservative. This may take them a while. In the meantime, President Obama is dropping the pretense that there is something to distinguish his campaign duties (fundraisers, online messages to supporters) and his presidential duties (addresses to large crowds, like the UAW). But not completely. He still won’t say Mitt Romney’s name.

Instead, he refers to Romney in the third person plural, as “folks,” or “politicians.” “It’s been funny to watch some of these politicians completely rewrite history now that you’re back on your feet,” Obama told the UAW gathering. “These are folks who said if we went forward with out plan to rescue Detroit, ‘You can kiss the American automotive industry goodbye.'” The only folks who wrote that line was Mitt Romney.

“Some politicians said we should, ‘Let Detroit go bankrupt,'” Obama said at another point in his speech to the UAW. The only “some politicians” was Romney, and he didn’t coin it. A headline writer at the New York Times topped an opinion piece that Romney wrote with that line. But never mind. You get the point.

If Romney ever does get a chance to return to his general election message, he will find that Obama has had plenty of time over the last several weeks to hone his own. As Adam Sorensen pointed out to me, there are lots of clear rebuttals to Romney’s one liners embedded in Tuesday’s speech. When Romney says that he believes in America or that Obama apologized for America, the President will retort, Romney gave up on an American industry. “I placed my bet on American workers,” Obama said Tuesday, again. “And I’d make that same bet again any day of the week.”

When Romney says he is for restoring American greatness, Obama will say the country should not look back. “We will not settle for a country where a few people do really well, and everyone else struggles to get by,” Obama said Tuesday. “We will not go back to an economy weakened by outsourcing, bad debt and phony profits.”

Those are the battle lines. At this point, no one is quite sure when the battle will begin once again.